Intelligent lighting has become widespread, and RF communication is a technology widely used for remote management of lighting devices. Instead of controlling the power (e.g. 230V supply) to the lighting device, the recent trend has moved towards directly controlling the light source or lighting device (i.e. the exchangeable lighting element lighting device) by sending an RF control signal to the lighting device.
It is preferable that the performance of an RF antenna in such a lighting device is not disturbed by other lamp components made from electrically conductive materials (or non-conductive materials that may lower the Q factor or resonance frequency) which, for example, could shield the RF signal in certain directions or change the resonant frequency of the RF antenna, and thus significantly influence the RF communication with remote controls or other lighting devices. Thus, it is preferred that the RF antenna radiates with significant directive gain in a large solid angle.
WO2013153522 describes a lighting device with a first antenna arrangement and a second antenna arrangement. Wherein a heat sink and a lamp foot form the second antenna arrangement, and the second antenna arrangement communicate with a remote control. The first antenna arrangement connects to a control unit in the lamp and is arranged in close vicinity of the second antenna arrangement for allowing near-field coupling of a radio frequency signal provided by the second antenna to control the at least one light source.